Change Facebook feed to Graph API v2

[rogeriopradoj]

As getting #hashtags are not allowed in Facebook API (even if trying to use deprecated v1.0 http://thenextweb.com/facebook/2015/04/03/facebook-might-be-shutting-down-access-to-hashtags-in-its-api/), this PR does:

• allow page search (pre-fixed with !) using API v2
• update @username search to use API v2
• remove #hashtag search

I think perhaps even the @username search option should be removed from the project (because it's not bringing any data).

[rogeriopradoj]

Hi, thanks @pavelk2 .

Do you think it's the right thing to remove Facebook @username option? Or it's better to keep it this way for now?

Best regards!

[pavelk2]

Hi @rogeriopradoj Let's keep it for now.